Fire-alarm telegraph



(No Model.)

B. ROGERS.

FIRE ALARM TELEGRAPH.

Patente d Sept. 18, 1883.

PATENT Fries.

EDWIN scenes,- or BROOKLINE, MASSACHUSETTS.

FIRE-ALARM TELEGRAPH.

SPECIFICATION forming part of Letters Patent NO: 285,076, datedSeptember 18, 1883.

Application filed April 24, 1852. (No model.)

To all whom, it may concern.-

Be it known that I, EDWIN ROGERS, of Brookline, county of Norfolk, Stateof Massachusetts, have invented an Improvement in Fire-Alarm Telegraphs,of which the following description, in connection with the accompanyingdrawings, is a specification.

My invention, relating to fire-alarm telegraphs, has for its object tocause a groundcircuit to be made automatically if the metallic circuitbe broken when the box is operated to send a signal, theground-connection being removed if the regular or main metallic circuitis complete, and it being applied only at the box which is operated.

The invention consists, partly, in the combination, with the usualbreak-wheel for automatically breaking the main or metallic circuit, ofa ground branch so connected with the said break-wheel as to have itsconnection with either end of the metallic circuit controlled by thesaid wheel, the said ground branch also being provided with an electricswitch or circuit-closer controlled by an electro-magnet in the mainmetallic circuit and by the mechanism or starting-lever of the box insuch manner that if the main circuit be broken and the starting-leversubsequently operated the said switch will close the said branch circuitto the ground; but if the circuit be closed when the said starting-leveris operated the said grounding branch will not be closed by the switch,and the box will consequently operate in the regular main circuitexactly as if not provided with my improvement.-

The invention also conslsts in the combination of the said switchcontrolled by an electro-magnet in the main circuit and by the mechanismof the box with a locking device to engage the said switch and retain itin the position governed by the condition of the said electro-magnetwhen the 131111 is operated, regardless of the subsequent changes incondition of the said magnet produced in the oper ation of the box tosend its Signal.

Figure 1 is a front elevation of a signal-box provided with thisinvention, showing the grounding-circuit in operation, the main metalliccircuit having been broken when the boxqwas'started; Fig. 2 a detailshowing the switch in the position assumed when the box is not inoperation, and Fig. 3 a diagram showing the circuit through the said boxand the central station where the signals are received from it.

The main portion of the signal-box (shown in Fig. 1) may be of any usualconstruction, it being shown as essentially the same as in LettersPatent No. 92,275, July 6, 1869, to

which reference may be had, the pull or start;

ing lever a being mounted on a shaft, 1), connected with anactuating-spring, c, in such manner that the movement of the said levera in the direction of the arrow, Fig. 1, winds up the said spring,which, by its elastic force, causes the said pull a to return in thedirection opposite the arrow.

The shaft b is provided with a segmental gear, (I, meshing with a pinionon an arbor, a, carrying the break-wheel f, the said pinion having aratchet-connection with the said arbor, so that it turns loosely thereonwhen the lever a is moved in the direction of the arrow, winding upthcspring 0, but causes the said arbor e to turn with it when the saidlever to and connected parts I) (I move in the opposite directionactuated by the spring 0 The arbor e is provided with a gear, 9, meshingwith a pinion on the arbor of the scapewheel h, which, in connectionwith the pendulum or governor z, regulates the movement of spring, a,(see Fig. 3,) and by wires '5 6 to the switch-magnet 0, the otherterminal of which is connected by wire 7 with the binding-post 8 andmain line L, leading 011 to the next box or station. T

A ground contact-spring, p, rests in contact with the side of themetallic periphery of the break-wheel f, and is in electrical contacttherewith during its entire rotation, while the contact of the springs ma therewith is broken as each successive notch in the periphery of thesaid wheel passes under them. The said grounding-spring is connected bywires 13 14: with a spring, 0*, a corresponding spring, 8, (see Fig. 3,)parallel therewith, being connected by wire 15 with the binding-post 16,connected with the ground.

The coils of the tapbell magnet may be in cluded in the wires 3 and 15,if desired, to sound the signal caused by the break-wheel f in the usualmanner. The armature-lever t of the ground-switch magnet 0 is providedwith an anvil or contact-piece, a, for the springs 0' 3, arranged tomake electrical connection between them when the said armature isretracted or remote from the poles of its magnet, as shown in Fig.1,but'to leave the said springs insulated and the ground-circuit openbetween them when the said armature is held at'the poles of its magnet,as shown in Fig. 2.

An arm, a, connected with the starting-lever a, rests on thearmature-lever 16, holding it up to the said magnet 0 when the box is inits normal condition, the spring 0, having run down it, overcoming theretractor of and hold ing the said armature-lever at the poles of itsmagnet, and retaining the grou1nl-circuit broken at 0' s, as shown inFig. 2, whether the main line is broken or not and the magnet 0magnetized or not. A l ocking device, 20, shown as a spring-arm,provided with a wedge-like point, '10, also has its end engaged by thearm a, and is held thereby disengaged from the cooperating pin orprojection t on the armaturelever zwhen the said starting-lever is inits normal position, as shown in Fig. 2. \Vhen 'the said starting-levera is raised, as shown in Fig. 1, the locking device w will engage thesaid pin t and retain'tlie armaturelever 1; in whatever position it maybe when the said le ver a is raisedthat is, if the main line L bebroken, the magnet 0 is demagnetized, and the armature-lever willconsequently not be attracted, and will follow the arm a in its up wardmovement, the parts being so arranged that in such movement theprojection t will pass the point wof the locking device before the saidlocking device is permitted by the said arm a to move into the path ofthe said projection t.

It, on the other hand, the main line L is intact when the lever a israised, the armature twill be held by the attraction of its magnet 0 inthe position shown in Fig. 2 until the locking device w is disengaged bythe arm a and engages the projection t on the opposite side to thatshown in Fig. 1. The said locking device will thus retain thearmature-lever t in whatever position it may be when the arm a israised. If the line be intact, it will retain it in the position shownin Fig. 2, and the ground-circuit will be open, and consequentlyinoperative, the box operating in the main line exactly as if notprovided with the said ground-circuit. If, on the other hand, the mainline be broken when the pull a is operated, the armature 1ever 15 willbe moved to and locked in the position shown in Fig. 1, closing the saidgro u11d-circuit, so that the break-wheel f will operate to make andbreak the connection between the said ground-circuit and that one of thesprings m or a which is connected with the unbroken portion of the mainline L.

At the central station, where the signals are received from the box orboxes, the main battery B (see Fig. 3) in the main line L will have itsmiddle portion connected with the ground, as shown in this instance bythe switch S, and receivirig-instruments or relays R R will be placed inthe main line L at either side of the said battery. The main line L isin this instance shown as broken at 20, so that all the magnets in thecircuit, including the magnets 0 of all the boxes, are demagnetized.Consequently when the starting-lever a of any box is operated thearmature 26 will be moved by its retractor to the position shown in Fig.1, and locked there by the locking device 10, thus retaining thegrounding branch closed at as, regardless of any subsequent changes inthe condition of the magnet 0. The circuit will thus be closed from theground at E (see Fig. 8) through one portion of the main battery .13,relay R to the spring a, break-wheel 1',

spring 1), wires 13 14, spring 1, anvil-piece a, spring 8, wire 15, andground E, connected with the binding-post 16. As soon as the break-wheelf begins to revolve the circuit will be broken between the springs a andp as each notch passes under the spring 12, leaving it insulated in theusual manner, so that the signals will be given by the relay R as if noaccidental break had occurred in the main line L. If the main line hadbeen broken at the other side of the box, the breakwheel f springs ands; but the movements of the ar mature-lever t and the locking deviceware so timed that the projection will have passed and been engaged bythe projection 20 of the locking device before the anvil-piece ittouches the springs 1- s, and the upper inclined surface of the saidprojection 10 will act with sufficient power to force the saidarmature-lever back and retain the circuit closed at as a, in oppositionto the attraction of the magnet 0 produced by the said closing of thecircuit.

1 am aware that a signal-box has been made in which a ground-connectionis made at the signal-box when a signal is given, but the said groundconnection is made even when the main line is intact. The box alwaysoperating in the same manner as the one herein described, operates whenthe main line is accidentally broken-a method of operation which isattended with difficulties which are overcome by my invention, in whichthe ground-circuit is employed only when the main metallic circuitfails, the said groundcircuit being applied automatically whennecessary, and being auto- 2. In a fire-alarm signal-box, thecombinamatically retained inoperative when not needed.

By the term starting-lever or .pull I mean the device that is moved bythe operator when desired to have the box send its signal. Theground-circuit controlling switch 1* s t a has been described ascontrolled electrically by the current in the main circuit andmechanically by the starting-lever of the box, this being, in thepresent instance, the most convenient portion of the box-operatingapparatus for accomplishing this result. It is obvious, however, thatany other portion of the mechanism of the box, or that a special devicevoperated thereby for the purpose, might be employed to mechanicallycontrol the said switch, it being necessary only that the said switchshall be held mechanically in one position when the box is at rest,regardless of the condition of its electrical controlling device ormagnet, but that immediately when the box is started it shall be lockedand retained duringthe subsequent operation of the box in a conditiondetermined .by the state of its electrical controlling device at themoment when the said box was started. a

The herein-described signal-box will commonly be used in the system inwhich an operator is constantly in attendance at the central station,and the ground will normally be removed from the middle of the batteryB, the switch S being open, and only one relay will commonly be employedin each circuit. When, however, the central operator discovers that acircuit is broken, he immediatelyswitches on a ground-connection at themiddle of the battery and places a relay in circuit at each end thereof,as shown in Fig. 3, the line remaining in this condition until the breakis discovered and repaired.

1. In a fire-alarm signal-box, the combination, with the break-wheel,its actuating mechanism, and starting-lever or pull, of a groundcircuitwire and electric switch or circuitcloser therein, automaticallycontrolled by an electro-magnet in the main circuit, and by the said boxmechanism, substantially as and for the purpose described.

tion, with the main normally-closed metallic circuit and break wheeltherein, of a grounding-circuit adapted to co-operate with the saidbreak-wheel, a circuit-closer or switch in the said grounding-circuit,and a controlling electro-magnet for the said switch in the said maincircuit, substantially as and for the purpose described.

3. The combination of the main metallic circuit, the signal-box therein,the groundingcircuit, the circuit-closer therein, and its con trollingelectromagnet in the said main circuit, with mechanical controllingmechanism for the said circuit-closer, whereby it is removed fromcontrol of the said electro-magnet,

except while the box is in operation sending trolled by the saidbreak-wheel, and the elec:

tric switch or circuit-closer between the said contact-piece and theground, combined with the switchcontrolling electro magnet, thestarting-lever or pull of the box, and the look ing device for the saidswitch, controlled by the said starting -lever, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thepresence of two sub scribing witnesses.

EDWIN ROGERS.

\Vitnesses:

J os. P. LIVERMORE, W. H. SIGSTON.

